1. Field of the Invention
The technical scope of the present invention is that of openings for military vehicles, such as access hatches to enter to vehicle or hatches providing an external view.
2. Description of the Related Art
A hatch of this type is generally a panel of substantial mass which requires opening assistance means and shock-absorbing means for the opening and closing phases because of the mass in motion.
Shock-absorbing means are known that comprise torsion blades. This technology is satisfactory but is complicated to define and implement.
Belleville washers have been proposed for use in door opening and closing systems.
Thus, patent FR-2860037 describes a system in which these washers are used to restore a closing torque on a door. To damp the movement of the door, this patent describes complex hydraulic means incorporating a fluid compression chamber and an expansion chamber.
U.S. Pat. No. 6,394,435 proposes the use of Belleville washers in combination with an elastomer. The role of the washers is to support the static mass so as to isolate the elastomer from the static forces. In the application described, Belleville washers are linked to a heavy mass and the displacements of this mass cause these washers to be compressed.
None of these documents describes the damping of the stroke of a hatch during the opening and closing of said hatch.